The present invention relates to a remote control device for controlling an electronic device, and more particularly, to a remote control device for controlling an AV (audio visual) device such as a VCR and a stereo.
Remote control devices are widely used to remotely control AV devices such as television sets, video recording/playback devices, and stereo recording/playback devices. A remote control device for controlling such an AV device includes a power button, volume control buttons, channel selection buttons, and various other control buttons. For example, when the remote control device is used to control a video player, the remote control device further includes various control buttons such as a play button, a fast-forward button, and a rewind button.
However, control buttons provided on such a conventional remote control device can output only a digital signal representing whether or not a control button is pressed. Therefore, in order to realize a function such as a rewinding operation at different levels such as normal speed, double speed, and quadruple speed, it is required to provide as many control buttons for one function as there are levels for that function. Thus, the remote control device needs a large number of control buttons, and it becomes complicated for a user to operate the remote control device. In particular, when a single remote control device is used to control a plurality of electronic devices such as a television set and a video recording/playback device, a very complicated operation is required to use the remote control device.
It is an object of the present invention to provide a remote control device which can be used in a simple fashion to control a large number of functions.
According to an aspect of the present invention, in order to achieve the above object, a remote control device for controlling an electronic device includes an analog switch having an operating element capable of being passed down and a pressure-sensitive resistor for outputting a signal having various levels depending upon a pressing force applied to the operating element.
In this remote control device according to the present invention a control button can be formed of the analog switch including the pressure-sensitive resistor thereby making it possible to use one button for a plurality of functions depending upon the pressing force applied to the operating element. Thus, it is possible to reduce the number of buttons, and a user can easily operate the remote control device in a simpler fashion. For example, in the case where the analog switch is used in a rewind button, it becomes possible to use the same rewind button to control the rewinding operation at various speeds such that when the rewind button is pressed with a weak force, a normal-speed rewind command is output, medium-force pressing generates a double-speed rewind command, and strong-force pressing generates a quadruple-speed rewind command. Thus, it becomes possible to control various functions using a smaller number of control buttons in a simpler fashion.
The pressure-sensitive resistor may be realized in various ways. For example, the pressure-sensitive resistor may be realized using an element whose conductivity various depending upon the pressure applied to it. Alternatively, the pressure-sensitive resistor may also be realized by employing a structure in which the contact area between a resistor and a conductive element is varied depending upon the applied pressure.
Preferably, the remote control device includes an analog-to-digital (A/D) converter for converting an analog signal output from the analog switch into a digital signal.
More specifically, the output signal of the pressure-sensitive resistor, which varies continuously in response to the applied pressure, is classified into one of predetermined voltage levels by performing A/D conversion using the A/D converter. Thus, it becomes possible for the remote control device to output a digital signal with one of a number of discrete levels.
An advantage of outputting a digital signal with one of a number of discrete level from the remote control device is that the output signal corresponding to the pressing force applied to the operating element is correctly transmitted to the electronic device without being affected by noise.
The remote control device preferably further includes a level correction unit for correcting the upper and lower limits of the analog signal output from the analog switch to corresponding calibrated levels.
More specifically, variable resistors are disposed in parallel with the pressure-sensitive resistor, and the resistance of the variable resistors is adjusted so that the output level of the pressure-sensitive resistors is adjusted to a correct level thereby ensuring that the output signal level precisely corresponds to the pressing force regardless of variations or deviations in the resistance.
The level correction unit is disposed at a preceding stage of the A/D converter so that a signal precisely corresponding to the applied pressing force is output.
The remote control device may be employed to control various types of electronic devices. In particular, the remote control device may be advantageously used to control an information reading/writing device for reading and/or writing information such as a sound or an image from/onto a recording medium.
Examples of such information reading/writing devices include a CD/DVD player for reading data recorded on an optical disk such as a compact disk, a CD-ROM, a DVD, and a DVD-ROM serving as a recording medium, and a video record/playback device for reading and/or writing data from/into a tape-shaped recording medium such as a videotape.
The advantage of employing the remote control device according to the present invention to control such an information reading/writing device is that a large number of functions such as a tape fast-forward operation, a tape rewind operation, and a skipping operation of musical pieces recording on a compact disk can be realized in a simple fashion.
When the electronic device to be controlled is one of such information reading/writing devices, it is preferable that an analog switch according to the present invention be disposed in a retrieval control button for retrieving information recorded on a recording medium or disposed in a stop button for stopping a data reading or writing operation from or to, respectively, the recording medium.
In general, the retrieval operation needs a fast-forward operation, a rewind operation, and a skip operation, and it is desirable that these operations can be performed at a desired speed selected from normal, double, and quadruple speeds. By employing the analog switch in the control buttons for controlling such operations, it becomes possible to control the retrieval speed at a desired level selected from predetermined discrete levels. This allows a user to control the operation in an easier and more natural fashion.
When the analog switch is employed in the stop bottom, it becomes possible to control the stopping operation in a desired mode selected from multiple modes including, for example, a pause mode and a completely stopped mode.